APPARATUS AND METHOD FOR NON-COMPLIANT OBJECT DETECTION

• US 20150054453A1
• Filed: 07/18/2014
• Published: 02/26/2015
• Est. Priority Date: 08/23/2013
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Kallal, Edward Kenneth, Tseng, Ryan, WHITE, Mark D. II, Maalouf, Joseph N.
• Granted Patent: US 9,793,717 B2
• Time in Patent Office: Days
• US Class Current: 320/108
• CPC Class Codes: G01R 21/01 in circuits having distributed constants G01R21/04, G01R21/07, G01R21/09, G01R21/12 take precedence
• CPC Class Codes: G01R 29/0814 Field measurements related to measuring influence on or from apparatus, components or humans EMC, EMI and similar testing in general G01R31/001, e.g. in ESD, EMI, EMC, EMP testing, measuring radiation leakage; detecting presence of micro- or radiowave emitters; dosimetry; testing shielding; measurements related to lightning
• CPC Class Codes: G01V 3/12 operating with electromagnetic waves operating with millimetre waves G01V8/005
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/40 using two or more transmitting or receiving devices H02J50/50 takes precedence
• CPC Class Codes: H02J 50/60 responsive to the presence of foreign objects, e.g. detection of living beings
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/007 Regulation of charging or discharging current or voltage
• CPC Class Codes: H04B 5/24 Inductive coupling
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

An apparatus and method for lost power detection are described. In one implementation, an apparatus for wireless transferring power comprises a wireless power transmitter configured to wirelessly transmit power at a power level sufficient to power or charge a chargeable device. The apparatus further comprises a controller configured to determine a first and second power difference between a first and second power measurement and the second and a third power measurement of the power level provided by the wireless power transmitter at a first, second, and third sample time, respectively. The controller is further configured to determine a transmitter power difference between the first power difference and the second power difference. The controller is further configured to determine an absence or a presence of an object that affects consumption of power transmitted by the wireless power transmitter based at least on the transmitter power difference Δ_T.

Claims

1. An apparatus for wirelessly transferring power, the apparatus comprising:

a wireless power transmitter configured to wirelessly transmit power at a power level sufficient to power or charge a chargeable device positioned within a charging region; and

a controller circuit operationally coupled to the wireless power transmitter and configured to;

determine a first power difference Δ

_1(PTU) between a first power measurement P_1(PTU) of the power level provided by the wireless power transmitter at a first sample time T₁ and a second power measurement P_2(PTU) of the power level provided by the wireless power transmitter at a second sample time T₂,

determine a second power difference Δ

_2(PTU) between the second power measurement P_2(PTU) and a third power measurement P_3(PTU)of the power level provided by the wireless power transmitter at a third sample time T₃,

determine a transmitter power difference Δ

_T between the first power difference Δ

_1(PTU) and the second power difference Δ

_2(PTU), and determine an absence or a presence of an object that affects consumption of power transmitted by the wireless power transmitter based at least on the transmitter power difference Δ

_T.

2. The apparatus of claim 1, wherein the controller circuit is further configured to determine a receiver power difference Δ

_R of the chargeable device, wherein the receiver power difference Δ

_R is indicative of a difference between first and second power differences at the chargeable device.

3. The apparatus of claim 2, wherein the controller circuit is further configured to determine that the transmitter power difference Δ

_T exceeds a threshold value before determining the receiver power difference Δ

_R.

4. The apparatus of claim 2, wherein the controller circuit is further configured to determine if a difference Δ

_TR between the transmitter power difference Δ

_T and the receiver power difference Δ

_R exceeds a threshold value.

5. The apparatus of claim 4, wherein the controller circuit is further configured to:

determine one or more subsequent differences Δ

<sub>TR—

N</sub> based on one or more subsequent transmitter power differences Δ

<sub>T—

N</sub> and one or more subsequent receiver power differences Δ

<sub>R—

N</sub>, wherein N is a positive integer,

determine an average of the difference Δ

_TR and the one or more subsequent differences Δ

<sub>TR—

N</sub>,

adjust the threshold value based at least in part on the one or more subsequent receiver power differences Δ

<sub>R—

N</sub>, and

determine if the average of the difference Δ

_TR and the one or more subsequent differences Δ

<sub>TR—

N</sub> exceeds the adjusted threshold value.

6. The apparatus of claim 4, wherein the object comprises a non-compliant object and wherein the controller circuit is further configured to determine the presence of the non-compliant object if the difference Δ

_TR exceeds the threshold value.

7. The apparatus of claim 1, wherein the wireless power transmitter turns off, adjusts the power level, and/or changes a state of transmission of power from the wireless power transmitter to the chargeable device if the controller circuit determines the presence of the non-compliant object within the charging region.

8. The apparatus of claim 2, wherein the controller circuit is further configured to determine if the receiver power difference Δ

_R exceeds the transmitter power difference Δ

_T multiplied by a proportional factor value, k, wherein k is any fraction between 0 and 1.

9. The apparatus of claim 1, wherein the power level is based on a current driven into a coil of the wireless power transmitter.

10. The apparatus of claim 1, wherein the controller circuit is further configured to synchronize a clock of the wireless power transmitter with a clock of the chargeable device and/or account for a time synchronization difference between one or more of the first, second, and third sample time at the wireless power transmitter, T₁, T₂, and T₃ and one or more of a first, second, and third sample time at the chargeable device.

11. A method for wirelessly transferring power, the method comprising:

wirelessly transmitting power at a power level sufficient to power or charge a chargeable device positioned within a charging region;

determining a first power difference Δ

_1(PTU)between a first power measurement P_1(PTU) of the power level provided by a wireless power transmitter at a first sample time T₁ and a second power measurement P_2(PTU) of the power level provided by the wireless power transmitter at a second sample time T₂;

determining a second power difference Δ

_2(PTU) between the second power measurement P_2(PTU) and a third power measurement P_3(PTU) of the power level provided by the wireless power transmitter at a third sample time T₃;

determining a transmitter power difference Δ

_T between the first power difference Δ

_1(PTU)and the second power difference Δ

_2(PTU); and

determining an absence or a presence of an object that affects consumption of power transmitted by the wireless power transmitter based at least on the transmitter power difference Δ

_T.

12. The method of claim 11, further comprising determining a receiver power difference Δ

_R of the chargeable device, wherein the receiver power difference Δ

_R is indicative of a difference between first and second power differences at the chargeable device.

13. The method of claim 12, further comprising determining that the transmitter power difference Δ

_T exceeds a threshold value before determining the receiver power difference Δ

_R.

14. The method of claim 12, further comprising determining if a difference Δ

_TR between the transmitter power difference Δ

_T and the receiver power difference Δ

_R exceeds a threshold value.

15. The method of claim 14, wherein the object comprises a non-compliant object, and the method further comprising determining the presence of the non-compliant object if the difference Δ

_TR exceeds the threshold value.

16. The method of claim 11, wherein the power level is based on a current driven into a coil of the wireless power transmitter.

17. An apparatus for wirelessly transferring power, the apparatus comprising:

means for wirelessly transmitting power at a power level sufficient to power or charge a chargeable device positioned within a charging region;

means for determining a first power difference Δ

_1(PTU)between a first power measurement P_1(PTU) of the power level provided by the transmitting means at a first sample time T₁ and a second power measurement P_2(PTU) of the power level provided by the transmitting means at a second sample time T₂;

means for determining a second power difference Δ

_2(PTU) between the second power measurement P_2(PTU) and a third power measurement P_3(PTU)of the power level provided by the transmitting means at a third sample time T₃;

means for determining a transmitter power difference Δ

_T between the first power difference Δ

_1(PTU) and the second power difference Δ

_2(PTU); and

means for determining an absence or a presence of an object that affects consumption of power transmitted by the transmitting means based at least on the transmitter power difference Δ

_T.

18. The apparatus of claim 17, wherein the power level is based on a current driven into the transmitting means.

19. The apparatus of claim 17, further comprising means for determining a receiver power difference Δ

_R of the chargeable device, wherein the receiver power difference Δ

_R is indicative of a difference between first and second power differences at the chargeable device.

20. The apparatus of claim 19, further comprising means for determining if a difference Δ

_TR between the transmitter power difference Δ

_T and the receiver power difference Δ

_R exceeds a threshold value.